单项选择题
A.temperature B.velocity C.density D.viscosity
A non-return valve in the air delivery line near to the...
单项选择题A non-return valve in the air delivery line near to the compressor must be （）type similar to the compressor discharge valve.
A.the low inertia B.the high inertia C.the low velocity D.the high velocity
A （） in the air delivery line near to each compressor i...
单项选择题A （） in the air delivery line near to each compressor is essential.
A.butterfly valve B.globe valve C.gate valve D.non-return valve
Adequate attention must be given to the water cooling s...
单项选择题Adequate attention must be given to the water cooling system of the air compressors, for （） can cause condensation on the cylinder walls.
A.overcooling B.poor cooling C.overloading D.unloading
